Details

Autor(en) / Beteiligte

• Wang, T.
• Ma, Z.
• Rao, X.
• Jiang, D.
• Ren, Y.
• Liu, Y.
• Yu, K.Y.
• Cui, L.

Titel

Temperature-dependence of superelastic stress in nanocrystalline NiTi with complete transformation capability

Ist Teil von

• Intermetallics, 2020-12, Vol.127 (C), p.106970, Article 106970

Ort / Verlag

Barking: Elsevier Ltd

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Nanocrystalline (NC) NiTi were previously reported to obtain non-hysteretic superelasticity and nearly zero temperature-dependence of superelastic stresses. However, the influence of the non-transforming regions in the specimens was not ruled out. In this study, we fabricate NC NiTi specimens with grain size down to 15 nm by wire drawing and annealing. Our specimens have no detectable non-transforming regions and thus are of complete transformation capability. We demonstrate that the hysteretic superelasticity is observed in all specimens of different grain sizes and that the minimum temperature-dependence of superelastic stresses is 4.7 MPa/K. Possible reasons for the discrepancy have been discussed. [Display omitted] •Nanocrystalline NiTi SMAs of various grain sizes were fabricated by wire drawing and annealing, showing complete transformation capability.•Hysteretic superelasticity was observed in all specimens of different grain sizes (down to 15 nm), in contrast to previous reports.•The ds/dT was grain-size dependent and its minimum value is 4.7 MPa/K (grain size 15 nm), in contrast to previous reports.